# 1. 求 1 - 100 的和
theSum = 0
for a in range(1, 101):
    theSum += a
print(theSum)

# 2. 求 300 - 400 的和
theSum = 0
for a in range(300, 401):
    theSum += a
print(theSum)

# 3. 求 1 - 1000 的和
theSum = 0
for a in range(1, 1001):
    theSum += a
print(theSum)
